Cachexia causes extreme weight loss and muscle wasting. It is a symptom of various chronic conditions such as cancer, chronic renal failure, HIV, and multiple sclerosis.

Cachexia predominantly affects people in the late stages of serious diseases like cancer, HIV or AIDS, and congestive heart failure.

The Society on Sarcopenia, Cachexia and Wasting Disorders defines cachexia as “a multifactorial syndrome characterized by an ongoing loss of skeletal muscle mass (with or without loss of fat mass) that cannot be fully reversed by conventional nutritional support and leads to progressive functional impairment.”

The disease causes involuntary weight loss, muscle wasting, and often a decrease in body fat. The loss of skeletal muscle may lead to physical weakness and impairment.

According to estimates, more than 160,000 people are hospitalized with a cachexia diagnosis every year in the United States.

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Cachexia is a complex syndrome. Its exact causes may vary depending on a person’s physiology and the underlying illness associated with it.

However, some underlying factors remain consistent across different diagnoses:

  • increased metabolic rate and energy expenditure
  • reduced nutrient intake or availability
  • increased breakdown of muscle
  • prevention of muscle growth

Cachexia often occurs at the end stages of severe conditions.

A person with one of the following conditions should talk to their doctor about steps to take to prevent the development of cachexia, and how it may be managed if it develops:

Symptoms of cachexia include:

  • Involuntary weight loss: A person may lose weight despite getting adequate nutrition or a high number of calories.
  • Muscle wasting: This is the characteristic symptom of cachexia. However, despite the ongoing loss of muscle, not all people with cachexia appear malnourished. For example, a person who was overweight before developing cachexia may appear to be of average size despite having lost a significant amount of weight.
  • Loss of appetite or anorexia: A person with cachexia may lose their desire to eat any food at all.
  • Reduced functional ability: A person may experience symptoms of malaise, fatigue, and low energy levels. This may include generalized feelings of discomfort, extreme tiredness, or a lack of motivation.
  • Swelling or edema: Low protein levels in the blood may cause fluid to move into the tissue, causing swelling.

As cachexia is sometimes difficult to recognize, doctors use a variety of criteria for diagnosis. In the most common system, the person must meet two criteria. One is non-deliberately losing more than 5% of their body weight over 6-12 months. The other is a body mass index (BMI) of less than 20 in a person under 65 years old, or a BMI of less than 22 in a person over 65 years old.


The fat and muscle wasting in cachexia is serious and can potentially increase morbidity. Cachexia is a significant factor in around one-fifth of deaths due to cancer.

Complications of cachexia include:

  • diminished quality of life and loss of the ability to live independently
  • impaired response to treatments
  • reduced immunity
  • escalating symptoms of the underlying chronic condition
  • a reduced life expectancy from the underlying disease

Treatment of cachexia will often depend on its associated underlying condition.

Since many factors contribute to its cause, a person will most likely have a medical plan incorporating several types of therapy to treat the disease. Due to the complex nature of cachexia, simply increasing calorie consumption will often not be enough to stop weight loss and muscle degradation.

A 2019 review suggested that medical professionals pay greater consideration to behavioral and psychological factors when assessing cachexia and its treatment.

Some recommended steps to support a person with cachexia include:

  • Focusing on the social aspects of eating: People get pleasure from sitting together over a meal even when they are not in the mood to eat. Emphasizing the social importance of eating instead of the amount of food may help a person reposition their emotional and psychological relationship to eating.
  • Eating frequent small meals: People with cachexia are more likely to tolerate eating high-calorie meals in small portions throughout the day rather than three set meals. In addition, nutritional supplement drinks are available to increase calorie intake between the small meals.
  • Providing emotional support: The family of a person with cachexia should understand that, as an underlying disease progresses to its end stage, people will sometimes not want to eat. Once they reach this stage, friends and family should not force the person with cachexia to eat. Muscle wasting and weight loss will continue whether a person with the condition eats or not.
  • Using appetite stimulants: Medications, such as dronabinol, megestrol, and glucocorticoids can aid appetite in certain conditions and diseases. However, eating more will not stop the progression of symptoms or improve muscle wasting. An increased appetite may help a person participate in family and social meals and feel a little less isolated, which benefits mental health.
  • Encouraging light exercise: As long as the person can tolerate it, exercise might help build muscle mass. However, there is no evidence about the effectiveness of exercise as a measure against cachexia.

Cachexia is usually a side effect of an underlying medical condition, so the focus for prevention lies in keeping the underlying chronic condition at bay.

Some conditions, such as COPD or HIV, are potentially preventable. However, other conditions that cause cachexia are largely unavoidable, such as cancer, rheumatoid arthritis, and Crohn’s disease.

An active lifestyle with balanced nutrition may reduce the risk of a chronic condition that could lead to cachexia.

What is cancer anorexia-cachexia syndrome?

People who have cancer sometimes experience a condition known as cancer anorexia-cachexia syndrome (CACS). It is cachexia, but with anorexia as part of the syndrome. Like cachexia, increasing calorie intake alone does not reverse the severe muscle wasting CACS causes.

The characteristics of CACS include:

  • muscle wasting
  • weight loss
  • loss of appetite
  • severe weakness or loss of strength and low energy level/fatigue
  • poor response to chemotherapy with increased side effects

Due to the complex nature of CACS, a multi-factor, tailored treatment plan may yield more favorable results, according to a 2015 review.

Cachexia is an often irreversible condition that occurs during the late stages of serious illnesses, including cancer and HIV. It causes severe, involuntary weight loss and muscle wastage.

An approach to treatment incorporating a range of therapies can help. However, the best way to prevent cachexia is to reduce the risk of underlying conditions.